#ifndef RateTransposer_H
#define RateTransposer_H

#include <stddef.h>
#include "AAFilter.h"
#include "FIFOSamplePipe.h"
#include "FIFOSampleBuffer.h"

#include "STTypes.h"

namespace soundtouch
{

/// A common linear samplerate transposer class.
///
/// Note: Use function "RateTransposer::newInstance()" to create a new class 
/// instance instead of the "new" operator; that function automatically 
/// chooses a correct implementation depending on if integer or floating 
/// arithmetics are to be used.
class RateTransposer : public FIFOProcessor
{
protected:
    /// Anti-alias filter object
    AAFilter *pAAFilter;

    float fRate;

    int numChannels;

    /// Buffer for collecting samples to feed the anti-alias filter between
    /// two batches
    FIFOSampleBuffer storeBuffer;

    /// Buffer for keeping samples between transposing & anti-alias filter
    FIFOSampleBuffer tempBuffer;

    /// Output sample buffer
    FIFOSampleBuffer outputBuffer;

    BOOL bUseAAFilter;

    virtual void resetRegisters() = 0;

    virtual uint transposeStereo(SAMPLETYPE *dest, 
                         const SAMPLETYPE *src, 
                         uint numSamples) = 0;
    virtual uint transposeMono(SAMPLETYPE *dest, 
                       const SAMPLETYPE *src, 
                       uint numSamples) = 0;
    inline uint transpose(SAMPLETYPE *dest, 
                   const SAMPLETYPE *src, 
                   uint numSamples);

    void downsample(const SAMPLETYPE *src, 
                    uint numSamples);
    void upsample(const SAMPLETYPE *src, 
                 uint numSamples);

    /// Transposes sample rate by applying anti-alias filter to prevent folding. 
    /// Returns amount of samples returned in the "dest" buffer.
    /// The maximum amount of samples that can be returned at a time is set by
    /// the 'set_returnBuffer_size' function.
    void processSamples(const SAMPLETYPE *src, 
                        uint numSamples);


public:
    RateTransposer();
    virtual ~RateTransposer();

    /// Operator 'new' is overloaded so that it automatically creates a suitable instance 
    /// depending on if we're to use integer or floating point arithmetics.
    static void *operator new(size_t s);

    /// Use this function instead of "new" operator to create a new instance of this class. 
    /// This function automatically chooses a correct implementation, depending on if 
    /// integer ot floating point arithmetics are to be used.
    static RateTransposer *newInstance();

    /// Returns the output buffer object
    FIFOSamplePipe *getOutput() { return &outputBuffer; };

    /// Returns the store buffer object
    FIFOSamplePipe *getStore() { return &storeBuffer; };

    /// Return anti-alias filter object
    AAFilter *getAAFilter();

    /// Enables/disables the anti-alias filter. Zero to disable, nonzero to enable
    void enableAAFilter(BOOL newMode);

    /// Returns nonzero if anti-alias filter is enabled.
    BOOL isAAFilterEnabled() const;

    /// Sets new target rate. Normal rate = 1.0, smaller values represent slower 
    /// rate, larger faster rates.
    virtual void setRate(float newRate);

    /// Sets the number of channels, 1 = mono, 2 = stereo
    void setChannels(int channels);

    /// Adds 'numSamples' pcs of samples from the 'samples' memory position into
    /// the input of the object.
    void putSamples(const SAMPLETYPE *samples, uint numSamples);

    /// Clears all the samples in the object
    void clear();

    /// Returns nonzero if there aren't any samples available for outputting.
    int isEmpty() const;
};

}

#endif
